Banging from underneath when shifting

[GregWeld]

Originally Posted by GregWeld

Yeah -- but that's the driver side --- I learned a while ago (50 years?) that the passenger side loads pretty hard during throttle use.... LOL

Never mind -- it appears to have been taken from the front of the car looking rearward.... which would make that pic of the passenger side.

[Budweasel]

The picture is the passenger side. I was laying on floor in front of right rear tire. Sorry I couldn't get my camera and iPhoto to play together. I have an update available so maybe that will resolve my issues.

Today I took off the Caltrac at the axle spring perch on the passenger side so I could move the axle forward. I loosened the already "not tight" u bolt nuts and kicked the right tire forward so i could center the rear end. I lightly tightened u bolts and set car on ground, then bounced the rear a few times by pushing on bumper. I then proceeded to torque the u bolt nuts to 110 ft/lbs. I double checked measurements and now have the same distance from center of front wheel to center of rear wheel on both sides. I guess the car was crabbing before so now I'll be needing that alignment Greg mentioned.

I mounted the Caltrac bar onto the spring perch and went to adjust preload. The "bushing" on top is already against the top of the spring and I'm unable to adjust the bar, (I don't own a 1-1/8 wrench yet). I don't know anything about these things so I'll read up on adjusting them in a thread a found at yellow bullet forum. If I can't figure them out they will go away. I'm not sure they are helping anyway with the wheelspin I'm getting.

Something I didn't notice before is one nut is missing from the bottom shock mount on passenger side. The drivers side has a nut on both sides - passenger side just has one nut on the front side.

I will button up the rest of the loose / missing hardware tomorrow. Then I will borrow, or buy, an action camera so I can get video of the rear in motion. I will share with you what I am able to capture. Might be a few days though. Hopefully I can find a place to mount it that captures some evidence.

If this is in the wrong section I apologize. I thought it was a driveline issue... now I'm not sure.

[GregWeld]

The CalTracks are there to help you with WHEEL HOP --- not really "traction" bars .... They'll keep the leaf spring from wrapping up and creating the wheel hop - which if you experience violently -- will break parts like no tomorrow! Leave 'em on -- just get 'em set right.


NOW TO MY CONCERN.... maybe you explained it wrong - or I read it wrong -- but here's what I'm concerned about.


On the TOP of the spring - there should be a small "post" which fits into a hole in the spring perch mount on your axle. This is there to INDEX the rear end to the center of the springs (fore and aft). The U bolts simply hold the perch tight to the spring. The perches are welded on the axle tube with the correct (stock location from the factory) pinion angle (again - this is as from the factory when built).

My issue is I don't think you should have been able to move the AXLE fore or aft -- if it was properly indexed on the posts! Maybe the posts are missing?????

In order to see them -- you'd have to loosen the U bolts enough to allow the axle to go up away from the spring enough for you to see them (probably 1/2" or more). They need to be in place of your axle will move on the spring and just be out of alignment again.

[Budweasel]

Greg,

That is bad news. When looking up from under the spring I could see what looked to be a post or bolt that was bent nearly flat toward the rear of the car. That was my second indication the axle was not centered, which caused me to get out the plumb bob and measure everything I could. That is when I found the 7/8" variance.

Sounds like this spring issue has moved to priority one. Is the post part of the spring or is it a boss on the axle?

Is it possible the kick I described when going into fourth was the axle moving back on the spring? Maybe I just broke that part and the banging and axle misalignment are not directly correlated.

Thanks again for all your help and interest in this. I owe you guys a beverage. Maybe I can make good on that if any of you are doing St Louis leg of power tour.

[GregWeld]

Sorry Jason -- Your description isn't very good.... so I'm not sure what you're looking at from where.

You should have to SEPARATE the perch from where it sits on the spring.... and a post should be between there to index the axle.


http://www.google.com/url?sa=i&rct=j...27766519967673


The link should take you to a picture of a leaf spring -- you'll see the post in the middle -- on TOP of the spring. That post should fit in a hole that is in the perch welded to the axle.

Originally Posted by Budweasel

Greg,

That is bad news. When looking up from under the spring I could see what looked to be a post or bolt that was bent nearly flat toward the rear of the car. That was my second indication the axle was not centered, which caused me to get out the plumb bob and measure everything I could. That is when I found the 7/8" variance.

Sounds like this spring issue has moved to priority one. Is the post part of the spring or is it a boss on the axle?

Is it possible the kick I described when going into fourth was the axle moving back on the spring? Maybe I just broke that part and the banging and axle misalignment are not directly correlated.

Thanks again for all your help and interest in this. I owe you guys a beverage. Maybe I can make good on that if any of you are doing St Louis leg of power tour.

[Vince@Meanstreets]

very true.

[Budweasel]

I took a few pictures today to help with my inadequate vocabulary.

I ordered a new shock mounting bolt from QA1 this afternoon from Amazon. Should be here Thursday. Below are a few pictures. I'll report back after I get the shock mounted on Thursday.

Shock mount with no nut on rear facing side


Shock mount threads stripped


Shot of "stud" coming through Caltrac perch. This is what I was trying to describe. I don't know the proper terminology, bear with me. Also note the 1/4" of clean threads after torquing the u-bolts to 110.

[GregWeld]

The Caltrac is on the bottom of the spring -- and it's formed a sandwich with the perch on the axle -- with the spring being in the middle.

There is another bolt/stud like that on the top of the spring - that should fit up int the perch that is welded to the axle (hopefully)

[Budweasel]

I took spring down by backing off u-bolt nuts to end of u-bolt. Then I was able to see the boss on top of the spring that is supposed to go into the spring perch to locate it. Problem: no corresponding hole in spring perch. I guess this is not the correct rear end for this car.

It looks like this spring pad is an adapter of sorts. I looked it up and it's an Energy Suspension universal type application.

I don't know what else to do but button it all back up and make sure the u-bolts don't get loose again.

Here are some shots.
looking up above spring


closer shot of perch with no hole




mystery rear end

[GregWeld]

So the CalTrac has a locating hole and post off the bottom of the spring - and with that bolted to the axle housing via the U-bolts -- the rear end won't move - so it's "okay" - as long as those bolts stay torqued.

My guess is -- when they were loose - it was allowing some (minor) movement which is probably why that lower "post/bolt" was a bit damaged.

There appears to be a spacer in between the spring and the axle perch... and you can see that it has a hole in it. That would have sat over the post if there was one on the top of the spring. Sometimes those spacers are tapered and are used to get the pinion angle correct. Yours appear to just be spacers to lower the car half an inch or so.

Put some RED Loctite on those U-bolts so those nuts won't come loose again.